The Effect of Obesity on Short- and Long-Term Outcome after Surgical Treatment for Acute Type A Aortic Dissection

Background: A paradox of lower morbidity and mortality in overweight or obese patients undergoing cardiac surgery has been described; however, knowledge about the influence of obesity in patients with acute Type A aortic dissection (AAD) is limited. This study aimed to evaluate the effect of obesity on short- and long-term outcomes after surgical treatment for AAD. Methods: Between 01/2004 and 12/2022, 912 patients with a BMI of 18.5 or greater were operated on for AAD. Patients were grouped according to their BMI (normal weight: BMI 18.5-24.9, n = 332; overweight: BMI 25-29.9, n = 367; obesity class I: BMI 30-34.9, n = 133; obesity class II+: BMI >= 35, n = 67), and the obtained clinical and surgical data were compared. Results: Obese patients were younger at the time of AAD (p = 0.001) and demonstrated higher rates of typical cardiovascular comorbidities (arterial hypertension, p = 0.005; diabetes mellitus, p < 0.001). The most important preoperative parameters, as well as the surgical approach, were similar between all four groups. The occurrence of renal failure requiring dialysis was higher in patients with BMI >= 35 (p = 0.010), but the in-hospital (p = 0.461) and long-term survival (p = 0.894) showed no significant differences. Conclusions: There are no indications that the obesity paradox is applicable in the setting of AAD. Since obese patients are affected by AAD at a younger age, obesity might constitute a risk factor for AAD. However, obesity does not influence short- or long-term survival. Regardless of body weight, immediate surgical therapy remains the treatment of choice for AAD.